This application is to support studies of social and other factors contributing to heavy alcohol drinking among group-living pigtail macaques. We previously received two years of support to produce such drinking. We have developed two protocols which induce heavy, daily, alcohol-reinforced drinking among monkeys in social groups. We have measured BAC's as high as 282, and we have estimated (from consumption information) BAC's as high as 328 mg/d1. We find a clear, direct relationship of dominance rank to drinking; higher ranking animals drink more, perhaps because they have greater access to alcohol. Certain physical changes frequently seen in human alcoholism have occured: mild anemia, modest increases in AST (SGOT), reduce serum albumin, and partial hairlessness. The monkeys become ataxic and engage in play-fighting during intoxications. We have developed a control solution, matched in palatability and caloric content to the alcohol solution, which permits us to assess alcohol's pharmacologic reinforcement of drinking. We have now produced high-dose, alcohol-reinforced drinking in two monkey social groups. We now propose to form a new group from alcohol-naive monkeys and to observe intensively both alcohol consumption and social behavior (using ethological techniques developed in our laboratory). We will examine both the initiation and the maintenance of alcoholic-like drinking, inducing such drinking with a protocol slightly modified from that which we have been using. During initiation of alcoholic-like drinking we specifically will examine social dominance and its influences on access to alcohol. We also will define further the role of food-deprivation in the induction of alcoholic-like drinking by this paradigm. In addition, we will distinguish whether alcohol serves in this paradigm as a primary reinforcer of its own ingestion, or whether its reinforcing property arises from its prior association with food during food deprivation. During the maintenance of high-dose drinking, we will use ethological techniques to determine how day-to-day social interactions in the group affect alcohol consumption by group members, and how consumption levels affect (in a dose-response fashion) social interactions within the group. These new procedures for inducing alcoholic-like drinking permit for the first time the experimental investigation of social influences on the development of such drinking.